Some agencies are on track to miss DATA Act implementation timelines.

A law that requires federal agencies to make their spending data transparent to the public is unlikely to be implemented by its goal date, a new series of watchdog reports show.

The Digital Accountability and Transparency Act, passed in 2014, would require 24 major federal agencies to upload their spending data by May 2017. But many of them still face challenges related to lack of guidance and technological delays, according to a new report from the Government Accountability Office.

The Office of Management and Budget and the Treasury Department have been tasked with directing implementation of the DATA Act across agencies. The Labor and Housing and Urban Development departments will likely miss the mark, the report found; an audit from the Interior Department's Office of the Inspector General concluded it would likely miss the deadline as well because of a software upgrade that will delay implementation.

GAO acknowledged OMB and Treasury have taken critical initial steps toward implementation, including creating a Data Standards Committee that would create definitions for data reporting; that group had its first meeting in September and will continue to meet each month.

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Broadly, agencies faced challenges related to "systems integration issues, lack of resources, evolving and complex reporting requirements, and inadequate guidance," the report said. Agencies have been trying to address these problems by reworking internal policy and using outside resources.

It isn't the first time watchdogs have warned of DATA Act delays. This summer, for instance, GAO concluded Treasury wasn't monitoring agencies' implementation progress closely enough.

A DATA Act pilot intended to produce recommendations for how to reduce the reporting burden for agencies may also not proceed on time, GAO found. Though OMB, HUD and the General Services Administration have together made "significant progress" since April in designing that pilot, "further improvement is still needed," including the way findings from that pilot might be applied to other processes, the report said. For instance, the data collection related to procurement may not begin until January or February of 2017.

And OMB's definitions and standards for data "lack clarity which still needs to be addressed to ensure that agencies report consistent and comparable data," GAO found.

Across agencies, "technical software requirements for agency reporting are still evolving, so any changes to the technical requirements over the next few months could also affect agencies’ ability to meet the reporting deadline."